Children with meningomyelocele (MMC) almost always have associated Arnold Chiari malformations of the brainstem, with resultant compression of brainstem ventilatory control centers. As a result, patients with MMC have an increased incidence of central apnea and central hypoventilation. However, it is not known whether old children continue to have problems. We therefore performed polysomnography in 15 children with MMC. One child had severe obstructive sleep apnea, which resolved following tonsillectomy and adenoidectomy. Four other children had mild or borderline abnormalities.